Two-way enantioselective control in the epoxidation of alkenes with the keto bile acid-Oxone system.

Abstract

A number of 3-keto bile acid derivatives has been prepared and evaluated in the asymmetric epoxidation of unfunctionalized\ud
olefins with Oxone. The control of the enantioselectivity with the production of both enantiomers is strictly regulated by the bile acid\ud
inductor, as a function of substitution at carbons C(7) or C(12). Up to 98% ee has been achieved. The stereochemical outcome of the reaction\ud
may be rationalized in terms of spiro transition state model